A new class of Ce/MnOx nano-composite materials for the exhaust emissions control: Catalytic study with CO model compound

The effects of formulation on the physical-chemical properties and CO oxidation activity of Ce/MnOx nano-composite materials have been assessed. The study of the interaction pattern of the Ce/MnOx nano-composite with reagent and product molecules shows easy reactivity to CO (e.g., catalyst reduction), low mobility of lattice oxygen, and weak surface affinity to CO2. All these evidences signal an extrafacial redox path, triggered by oxygen ions in the neighboring of surface active MnIV sites and driven by adsorbed O2 species. A Langmuir-Hinshelwood-type mechanism that explains the empiric kinetics, fully predicting the CO oxidation performance of the Ce/MnOx catalyst in the range of 293-533K.